Working Paper

Plan Responses to Diagnosis-Based Payment: Evidence from Germany's Morbidity-Based Risk Adjustment

Sebastian Bauhoff, Lisa Fischer, Dirk Göpffarth, Amelie C. Wuppermann
CESifo, Munich, 2017

CESifo Working Paper No. 6507

Many competitive health insurance markets adjust payments to participating health plans according to their enrollees’ risk – including based on diagnostic information. We investigate responses of German health plans to the introduction of morbidity-based risk adjustment in the Statutory Health Insurance in 2009, which triggers payments based on “validated” diagnoses by providers. Using the regulator’s data from office-based physicians, we estimate a difference-in-difference analysis of the change in the share and number of validated diagnoses for ICD codes that are inside or outside the risk adjustment but are otherwise similar. We find a differential increase in the share of validated diagnoses of 2.6 and 3.6 percentage points (3-4%) between 2008 and 2013. This increase appears to originate from both a shift from not-validated toward validated diagnoses and an increase in the number of such diagnoses. Overall, our results indicate that plans were successful in influencing physicians’ coding practices in a way that could lead to higher payments.

CESifo Category
Social Protection
Public Finance
Keywords: health plan payment, risk adjustment, managed competition, diagnostic coding, German Statutory Health Insurance
JEL Classification: H510, I100, I130, I180